From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AB653C433DF for ; Tue, 16 Jun 2020 10:07:03 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 820DC20707 for ; Tue, 16 Jun 2020 10:07:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 820DC20707 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jl8UP-0006F3-5t; Tue, 16 Jun 2020 10:06:45 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jl8UO-0006Ey-Ka for xen-devel@lists.xenproject.org; Tue, 16 Jun 2020 10:06:44 +0000 X-Inumbo-ID: 1473bcd4-afb9-11ea-bca7-bc764e2007e4 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id 1473bcd4-afb9-11ea-bca7-bc764e2007e4; Tue, 16 Jun 2020 10:06:44 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 57284AD60; Tue, 16 Jun 2020 10:06:46 +0000 (UTC) Subject: Re: [RFC PATCH v1 1/6] sched: track time spent in IRQ handler To: Volodymyr Babchuk References: <20200612002205.174295-1-volodymyr_babchuk@epam.com> <20200612002205.174295-2-volodymyr_babchuk@epam.com> From: Jan Beulich Message-ID: <423db379-785d-d003-638c-223c4465e635@suse.com> Date: Tue, 16 Jun 2020 12:06:41 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200612002205.174295-2-volodymyr_babchuk@epam.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , Andrew Cooper , Ian Jackson , George Dunlap , Dario Faggioli , "xen-devel@lists.xenproject.org" , =?UTF-8?Q?Roger_Pau_Monn=c3=a9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On 12.06.2020 02:22, Volodymyr Babchuk wrote: > --- a/xen/arch/x86/irq.c > +++ b/xen/arch/x86/irq.c > @@ -1895,6 +1895,7 @@ void do_IRQ(struct cpu_user_regs *regs) > int irq = this_cpu(vector_irq)[vector]; > struct cpu_user_regs *old_regs = set_irq_regs(regs); > > + vcpu_begin_irq_handler(); > perfc_incr(irqs); > this_cpu(irq_count)++; > irq_enter(); > @@ -2024,6 +2025,7 @@ void do_IRQ(struct cpu_user_regs *regs) > out_no_unlock: > irq_exit(); > set_irq_regs(old_regs); > + vcpu_end_irq_handler(); > } This looks like a fight for who's going to be first/last here. I think you want to add your calls after irq_enter() and before irq_exit(). Jan